1. Field
The present application relates generally to implantable infusion devices.
2. Description of the Related Art
Implantable infusion devices have been used to provide a patient with a medication or other substance (collectively “infusible substance”) and frequently include a reservoir and a pump. The reservoir is used to store the infusible substance and, in some instances, a fill port is provided that allows the reservoir to be transcutaneously filled (and/or re-filled) with a hypodermic needle. The reservoir is coupled to the pump, which is in turn connected to an outlet port. A catheter or other device, which has at least one outlet at the target body region, may be connected to the outlet port. As such, infusible substance may be transferred from the reservoir to the target body region by way of the pump and catheter.
In some therapies, there is a need to deliver two or more distinct medications to different body sites or to the same site independently. With some pain management protocols, for example, it is desirable to deliver morphine and clonidine to a patient's intrathecal site. In certain cancer therapies, it may be desirable to deliver multiple medications to multiple sites. As a further example, insulin and glucogon may be administered sequentially to lower or to raise blood sugar in some diabetes therapies. Implantable infusion devices having two or more reservoirs, or two or more reservoir compartments, and two or more fill ports have been proposed in order to accommodate such therapies (collectively “multiple-reservoir implantable infusion devices”).
The present inventors have determined that one issue associated with multiple-reservoir implantable infusion devices is related to transcutaneous filling. In particular, the present inventors have determined that it can be difficult to distinguish between two or more fill ports during a fill or evacuation procedure. Regardless of the number of reservoirs and fill ports, another issue associated with conventional implantable infusion devices is post-implantation rotation of the device. Post-implantation rotation can make it difficult to locate a single fill port, if the fill port is not located in the center of the reservoir, to distinguish between multiple fill ports. Post-implantation rotation can also put strain on catheter, can pull the end of the catheter from its proper position (e.g. within spine), can cause catheter fatigue at the connection to the pump, which leads to breaks and leaks, can cause disconnections at the pump or at the spinal connection of a two-part catheter, and can cause tissue irritation or erosion in the pump pocket.